Measuring and indicating instrument



April 29, 1941. w, K 2,240,304

MEASURING AND INDICATING INSTRUMENT Filed July 50, 1938 12 LINE DRAWING 14 13 4 DEFLEC'TING COIL 1 1G- 1- 21 i6 Q 10 a/ z 11 16 "I I4 LINE DRAWING DEFLECTING con.

15 14 PROVIDES NON- LINEAR ELECTRO- STATIC FIELD fiPPL/L'D 14 M" vaz'rnaz 25 Fig.4.

Ml PROVIDES NON-LINEAR zggi'ai ELECTROSTATIC FIELD ELECTROSTATIC 26 1 F|ELD FPPE/ED JP vozvweg L Z645 23 25 flPPJJ/ED M vaz'rnez '1 za 3nnentor Winfield H.1foc

dflorneg Patented Apr. 29, 1941 UNITED MEASURING, Ann mmumemsmmm, winfilain. Koch; Haddonfield, N. J., assignor .to

Radio Corporation of A a i Delaware merica, a corporation of ApplicationJuIyBO, 193s, SerialNo. 222,109

Claims. (01; 250- 1:58)

or other'non-linear indication ofthe electrical characteristic under consideration. To this, end, in one embodiment of the invention, this deflecting plate is so contoured with respectto the other deflecting plates'of thetubathat the inter-plate electrostatic fleld varies non-linearly in accordance with the characteristic to be measured. In. an alternative embodiment, the, potential gradient between theopposite edges of this plate is such as to deflect the cathode ray in a vertical direction, for example, to positions indicative of the desired function.

A further feature is the provision of means for deflecting the cathode ray in one plane sothat-- a fluorescent line or the like maybeutilized in conjunction with a Scale for reading the indicated characteristic.

The-invention will be better understood from the following description considered in connec-,

tionwith the accompanying drawing andits scope is indicated by the appended, claims.

Referring to the drawing, Figure l is a perspective view of the cathode ray tube which is the basis ofgthe improved measuring instrument Figure 2 is a wiring diagram illustrating certain, connections of the instrument and also showing one of the deflecting :plates contoured in accordance with the function to be indicated,

of the cathode ray projected from the cathode J I. 1 a

yAsiis well known, the cathode ray would usually be inthe form of a spot more or less diago- 11 ally across the screen in response to variations of the;potentials applied to the deflecting electrodes 1 4-! 5' and. VI 6+! 1. In order to produce a straight line indication zllat the scale-l9, there is provided a pair of coils 2I22 connected to a source of alternating current, which function to deflect the ray in a horizontal direction independently of the action of the deflecting electrodes, thus permitting its position with respect to the scale 19 to be readily observed. A third Pair of de- -flecting,pl-ates may be used instead of the coils if desired. 7

It will, of course, understood that suitable potentials. are applied to the various electrodes .and coils of the. cathode ray tube, the circuits through which these potentials are applied having beenyomitted for, the reason that they are well known and are incidentally involved in the present invention.

' Asindicated by Fig, 2, the voltage to be measfured, which .;may be D. C. orv rectified and smoothed alternating voltage, is applied through i a biasbattery 23 to the deflecting electrodes l4,

l5 and 16, and there is applied through the battery 24 to the deflecting plat H a potential which produces an electrostatic field between electrodes l6 and" whose lines of force are substantially perpendicular to the normal axis of the beam and perpendicular to the lines of force produced by electrodes l4 and I5. The potential gradientof this field varies from point to point along a line intermediate the electrode perpendicularto-the horizontal deflecting plates I4 and [5, that is, the potential gradient is non-uniform alo rig this line. In the preferred case the non- 'Figure 3 differs from Fig. 2 in that oneof the deflecting plates is so constructed and energized that a desired potential gradient is established between its opposite edges, and

Figure 4 is similar to Fig. 3 but involves a uniformity is logarithmic. The potential due to thejvertical plates l6 and I1 affecting the beam as it moves horizontally varies inaccordance with this change in gradient, producing a vertisomewhat different method of establishing the" potential gradient along the electrode surface.

The cathode ray tube of Fig. 1 includes an envelope [0 within which are mounted a cathode I I, a grid or intensity control electrode 12, a first anode or focusing electrode [3, horizontal deflecting plates l4-| 5, vertical deflecting plates lB-l'l and a second anode l8 which may be associated with a fluorescent screen or the like for indicating on a scale IS the vertical position .caldeflection which is a function of the gradient, and hence of the surface contour of the plate".

Under'the'se conditions, the cathode ray is deflected horizontally in accordance with the potential of the source 25 and is deflected vertically in accordance with a non-linear function of this potential, the particular function indicated being determined by the surface contour of the plate IT.

The modification of Fig- 3 difiers from that of Fig. 2 in that the electrode is made in the form of a resistor element and the potential gradient between its opposite edges facing electrodes l4 and I5, respectively, is produced by current supplied from a source 26, thus establishing an electrostatic field having a similar gradient along a line perpendicular to the cathode ray.

Another suitable form of the non-linear defleeting electrode is shown by Fig. 4 wherein this electrod comprises opposed electrodes 21 and 28 for applying between the transverse edges of a bcdy 29 of carbon or the like a potential whereby the desired potential gradient along the surface of the plate I! is established. As herein combinations, and thus to obtain any desired time constant; because the proposed system involves but a slight modification of existing cathode ray tubes it is relatively inexpensive; since no delicate meter mechanism is used and since there are no mechanical moving parts the possibility of damage from overloading is greatly reduced; and by merely rotating the deflecting coils 2 I, 22 and the scale ['9 through 90 the symmetrical plates ld l5 can be used to provide linear displacement of the indication line 20.

I claim as my invention:

l. A cathode ray tube comprising means for producing a concentrated electron .ray beam; a first pair'of electrodes for deflecting said beam in a given direction in accordance with the amplitude of a voltage to be indicated; means including a-second pair of electrodes for establishing a constant electrostatic field whose lines of force are substantially perpendicular to said beam and to said given direction,- the intensity of said field being non-uniform in said given direction so that the deflection of said beam in said given direction produces a deflection in a direction perpendicular thereto, and auxiliary deflecting means operable on said beam to oscillate said beamin said given direction to produc an indicating line, the position of said line being a nonlinear function of the amplitude of said voltage to be indicated.

2. A cathode ray tube comprising means for producing a concentrated electron ray beam; a

pair of electrodes for deflectingsaid beam in a' given direction in accordance with an applied voltage; and means'including a second pair of electrodes for establishing a fixed electrostatic fieldwhose lines of force are perpendicularto said given direction and non-uniform in density along said given direction so that the position of said beam in a direction perpendicular to said given direction is a function solely of the deflection of said beam in said given direction.

3. A cathode ray tube comprising means for producing a concentrated electron beam; a pair of electrodes for deflecting said beam in a horizontal direction in a plane perpendicular to said electrodes; means including a second pair of elec trodes for establishing a fixed electrostatic field oi nonuniform intensity in said horizontal direction; and auxiliary deflecting means for independently deflecting said beam in a horizontal plane whereby an indicating line is produced whose vertical deflection is a function of the voltage applied to said first pair of electrodes.

4. A cathode ray devic comprising means for producing a. concentrated beam of electrons, a first pair of electrodes for deflecting said beam in a given direction, and means including a second pair of deflecting electrodes for establishing a fixed electrostatic field whose lines of force are perpendicular to said given direction and the axis of said beam, the potential gradient of said field being different at points along said given direction so that said beam is deflected in another direction perpendicular to said given direction as a function of its deflection in said given direction, andmeans for indicating only said deflection in said other direction, said deflection being a nonlinear function of the deflection produced by said first pair of electrodes.

5. A cathode ray tube comprising means for producing a concentrated electron beam; two pairs of deflecting electrodes; means for applying a voltage to be indicated to the first pair of electrodes; means for establishing a fixed potential between the second pair of electrodes; one electrode of said second pair being curved so as to produce an electrostaticfield of nonuniform in tensity along a line perpendicular to the first pair of electrodes and perpendicular to said beam so that the deflection of said beam in a direction perpendicular to said first electrode is determined by its position in said field.

6. A device of the character described in claim 4 in which said second pair of deflecting electrodes includes an electrode comprising a resistive material mounted on a conductive base and having an electrode in contact with the upper edge adjacent one of said first pair of defleeting electrodes.

7. A cathode ray tube comprising means for producing an electron beam; a fluorescent screen for producing a light image indicative of the position of said beam; means for establishing a steady electrostatic field whose lines of force are perpendicular to the axis of said beam and whose intensity is nonuniform in a horizontal direction; means for controlling the horizontal position of said beam in said field in accordance with a voltage or current to be indicated to produce a resultant vertical deflection the amplitude of which is determined by the field intensity at the given position of said beam; auxiliary deflecting means located between said screen and said'controlling means for independently oscillating said beam in a horizontal plane to produce an indicating line, the vertical displacement of said line being; a function of said voltage or current to be indicated.

WINFIELD R. KOCH. 

